Heikki Kovalainen showed his intentions with the third-fastest lap of 1m 16.248s to edge out Felipe Massa, who registered 1m 16.292s for Ferrari. The top four were thus covered by only 0.344s!
Late in the day Nico Rosberg jumped up to fifth for Williams with 1m 16.653s, then came Robert Kubica for BMW Sauber on 1m 16.834s and Fernando Alonso for Renault on 1m 17.498s. The top 10 was completed by Rubens Barrichello on 1m 17.511s for Honda, Mark Webber on 1m 17.798s for Red Bull, and Giancarlo Fisichella on 1m 17.835s for Force India.
The session was stopped for 10 minutes when just over half an hour remained, as FIA representatives examined a loose drain cover on the run up Beau Rivage towards Massenet.
Timo Glock was Toyotas lead runner on 1m 17.942s in 11th place, after 2004 winner Jarno Trulli hit a wall (probably at Portier) and damaged his left rear suspension. He languished in 16th place on 1m 18.360s as a result.
Jenson Button was 12th in the second Honda on 1m 18.153s, then came Sebastien Bourdais in the new Toro Rosso STR3 on 1m 18.245s, Nick Heidfeld, whose BMW Sauber rolled to a halt at Massenet late in the session after he had recorded 1m 18.263s, Williams Kazuki Nakajima (1m 18.274s), Trulli, Force Indias Adrian Sutil (1m 18.360s), Renaults Nelson Piquet (1m 18.955s) and Toro Rossos Sebastian Vettel (1m 19.176s).
David Coulthard was 20th having failed to set a time after his Red Bull glided to a halt down by the chicane early on.